The role of metronidazole in the treatment of periodontal diseases

Quorum-quenching enzyme Est816 assisted antibiotics against periodontitis induced by Aggregatibacter actinomycetemcomitans in rats

Introduction

Quorum-quenching enzyme Est816 hydrolyzes the lactone rings of N-acyl homoserine lactones, effectively blocking the biofilm formation and development of Gram-negative bacteria. However, its applications in the oral field is limited. This study aimed to evaluate the efficacy of enzyme Est816 in combination with antibiotics against periodontitis induced by Aggregatibacter actinomycetemcomitans in vitro and in vivo.

Methods

The antimicrobial efficacy of enzyme Est816 in combination with minocycline, metronidazole, and amoxicillin was determined using the minimum inhibitory concentration test. The anti-biofilm effect of enzyme Est816 was assessed using scanning electron microscopy, live/dead bacterial staining, crystal violet staining, and real-time quantitative PCR. Biocompatibility of enzyme Est816 was assessed in human gingival fibroblasts (HGF) by staining. A rat model of periodontitis was established to evaluate the effect of enzyme Est816 combined with minocycline using micro-computed tomography and histological staining.

Results

Compared to minocycline, metronidazole, and amoxicillin treatment alone, simultaneous treatment with enzyme Est816 increased the sensitivity of biofilm bacteria to antibiotics. Enzyme Est816 with minocycline exhibited the highest rate of biofilm clearance and high biocompatibility. Moreover, the combination of enzyme Est816 with antibiotics improved the antibiofilm effects of the antibiotics synergistically, reducing the expression of the virulence factor leukotoxin gene (ltxA) and fimbria-associated gene (rcpA). Likewise, the combination of enzyme Est816 with minocycline exhibited a remarkable inhibitory effect on bone resorption and inflammation damage in a rat model of periodontitis.

Discussion

The combination of enzyme Est816 with antibiotics represents a prospective anti-biofilm strategy with the potential to treat periodontitis.

Comparative Evaluation of Antimicrobial Efficacy of Triple Antibiotic Paste Herbal Combination and Camphorated Monochlorophenol as Intracanal Medicaments against Enterococcus faecalis in Deciduous Molars: An In Vivo Study

Aim

Compare the efficacy of triple antibiotic paste (TAP), herbal extracts, and camphorated monochlorophenol (CMCP) as intracanal medicaments against Enterococcus faecalis (E. faecalis) in deciduous molars.

Materials and methods

A total of 60 samples were collected from canals of first and second molars of 4-10-year-old children, with more than two-thirds root length, and fitting the inclusion criteria. Samples were collected at three intervals-S1 was collected just after access opening, S2 was collected after biomechanical preparation (BMP) and irrigation, and just before placement of medicament. Randomization was done to place the medicaments into three groups: group I-CMCP, group II-TAP, and group III-herbal combination. Sample S3 was taken 48 hours after removal of medicament from the canals. The collected samples were transported via Amies media to the laboratory, where they were anaerobically incubated for 24 hours. Growth of E. Faecalis was observed, and manual counting of the colony-forming unit (CFU) was done. The change in CFU in all samples was calculated, and the results were statistically analyzed.

Results

The results show that there is a change from S1 (TAP = 118.67 ± 122.48, herbal = 109.07 ± 106.43; CMCP = 110.73 ± 120.53) to S2 (TAP = 34.13 ± 63.47; herbal = 27.67 ± 39.39; CMCP = 16.40 ± 26.32) and S3 (TAP = 12.33 ± 24.82; herbal = 4.73 ± 12.78; CMCP = 3.40 ± 7.12). It is seen that there is a significant difference seen from S1 to S2 in all three groups (p ≤ 0.05) using repeated measure analysis of variance (ANOVA) test. This shows that all three medicaments were effective in reducing bacterial counts of E. Faecalis from sample S1 (pre) to S3 (post) significantly after exposure to root canal bacterial flora for 48 hours (2 days). The pairwise comparison of the change in CFU within each group, S1-S3, also shows significant changes. There is a significant decrease in CFU seen from S1 to S2 and S1 to S3 but not from S2 to S3 for all three groups, which was evaluated using the post hoc Bonferroni test. It was also observed that in between the canals, although there was a change from S1 to S3 in terms of the CFU, there was no significant difference in the decrease in the bacterial count when intercanal comparison was made. There was, however, a change that was seen to be significant when values from each canal were compared from S1 to S3.

Conclusion

All three medicaments have successfully shown a decrease in the numbers of E. faecalis, which the study aimed at checking. Although the effect varied intergroups, it was mild, so herbal alternatives could be used instead of antibiotics and CMCP. Also, because the local application is effective in controlling interappointment flare-ups, the medicaments can be successfully given without having to prescribe systemic antibiotics.

How to cite this article

Tawde MM, Lakade L, Patil S, et al. Comparative Evaluation of Antimicrobial Efficacy of Triple Antibiotic Paste Herbal Combination and Camphorated Monochlorophenol as Intracanal Medicaments against Enterococcus faecalis in Deciduous Molars: An In Vivo Study. Int J Clin Pediatr Dent 2024;17(3):243-254.

Drug-Loaded Chitosan Scaffolds for Periodontal Tissue Regeneration

Chitosan is a natural anionic polysaccharide with a changeable architecture and an abundance of functional groups; in addition, it can be converted into various shapes and sizes, making it appropriate for a variety of applications. This article examined and summarized current developments in chitosan-based materials, with a focus on the modification of chitosan, and presented an abundance of information about the fabrication and use of chitosan-derived products in periodontal regeneration. Numerous preparation and modification techniques for enhancing chitosan performance, as well as the uses of chitosan and its metabolites, were reviewed critically and discussed in depth in this study. Chitosan-based products may be formed into different shapes and sizes, considering fibers, nanostructures, gels, membranes, and hydrogels. Various drug-loaded chitosan devices were discussed regarding periodontal regeneration.

The Side Effects of the Most Commonly Used Group of Antibiotics in Periodontal Treatments

Antibiotic combinations are preferred for the treatment of periodontal diseases, with the aim of hitting the bacterial flora, according to its characteristics—aerobic, anaerobic, gram-negative, and gram-positive—with certain antibiotics that act on certain bacteria. The aim of this study is to analyze the side effects of the antibiotics used. Data on the side effects (preferably expressed in percentages) of some antibiotics, the favorites in periodontal recipes, are gathered from the literature. These data are listed according to the antibiotic used. In the case of providing a periodontal prescription, the patient is at risk of allergy (5%), nephritis (3%), hematological problems (2–2.5%), gastrointestinal problems (5.5%), disturbance in the nervous system (2%), allergic signs on the skin (5.5%), and problems with electrolytes displayed in lower percentages. Interaction with different medications is present in almost all cases. The influence on the body systems is 4% in total, the maximum value of which is expressed on the skin, and the minimum value is expressed in the nervous system. Cross allergies are at a high value because of the expressed structural similarity of antibiotics. Given a recipe, we have a balance of the percentage of side effects, the percentage of bacterial resistance, and the percentage of the success of the recommended dose of antibiotics.

Supportive periodontal therapy (SPT) for maintaining the dentition in adults treated for periodontitis

BACKGROUND

Periodontitis is a bacterially-induced, chronic inflammatory disease that destroys the connective tissues and bone that support teeth. Active periodontal treatment aims to reduce the inflammatory response, primarily through eradication of bacterial deposits. Following completion of treatment and arrest of inflammation, supportive periodontal therapy (SPT) is employed to reduce the probability of re-infection and progression of the disease; to maintain teeth without pain, excessive mobility or persistent infection in the long term, and to prevent related oral diseases.According to the American Academy of Periodontology, SPT should include all components of a typical dental recall examination, and importantly should also include periodontal re-evaluation and risk assessment, supragingival and subgingival removal of bacterial plaque and calculus, and re-treatment of any sites showing recurrent or persistent disease. While the first four points might be expected to form part of the routine examination appointment for periodontally healthy patients, the inclusion of thorough periodontal evaluation, risk assessment and subsequent treatment - normally including mechanical debridement of any plaque or calculus deposits - differentiates SPT from routine care.Success of SPT has been reported in a number of long-term, retrospective studies. This review aimed to assess the evidence available from randomised controlled trials (RCTs).

OBJECTIVES

To determine the effects of supportive periodontal therapy (SPT) in the maintenance of the dentition of adults treated for periodontitis.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 8 May 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2017, Issue 5), MEDLINE Ovid (1946 to 8 May 2017), and Embase Ovid (1980 to 8 May 2017). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) evaluating SPT versus monitoring only or alternative approaches to mechanical debridement; SPT alone versus SPT with adjunctive interventions; different approaches to or providers of SPT; and different time intervals for SPT delivery.We excluded split-mouth studies where we considered there could be a risk of contamination.Participants must have completed active periodontal therapy at least six months prior to randomisation and be enrolled in an SPT programme. Trials must have had a minimum follow-up period of 12 months.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results to identify studies for inclusion, assessed the risk of bias in included studies and extracted study data. When possible, we calculated mean differences (MDs) and 95% confidence intervals (CIs) for continuous variables. Two review authors assessed the quality of evidence for each comparison and outcome using GRADE criteria.

MAIN RESULTS

We included four trials involving 307 participants aged 31 to 85 years, who had been previously treated for moderate to severe chronic periodontitis. Three studies compared adjuncts to mechanical debridement in SPT versus debridement only. The adjuncts were local antibiotics in two studies (one at high risk of bias and one at low risk) and photodynamic therapy in one study (at unclear risk of bias). One study at high risk of bias compared provision of SPT by a specialist versus general practitioner. We did not identify any RCTs evaluating the effects of SPT versus monitoring only, or of providing SPT at different time intervals, or that compared the effects of mechanical debridement using different approaches or technologies.No included trials measured our primary outcome 'tooth loss'; however, studies evaluated signs of inflammation and potential periodontal disease progression, including bleeding on probing (BoP), clinical attachment level (CAL) and probing pocket depth (PPD).There was no evidence of a difference between SPT delivered by a specialist versus a general practitioner for BoP or PPD at 12 months (very low-quality evidence). This study did not measure CAL or adverse events.Due to heterogeneous outcome reporting, it was not possible to combine data from the two studies comparing mechanical debridement with or without the use of adjunctive local antibiotics. Both studies found no evidence of a difference between groups at 12 months (low to very low-quality evidence). There were no adverse events in either study.The use of adjunctive photodynamic therapy did not demonstrate evidence of benefit compared to mechanical debridement only (very low-quality evidence). Adverse events were not measured.The quality of the evidence is low to very low for these comparisons. Future research is likely to change the findings, therefore the results should be interpreted with caution.

AUTHORS' CONCLUSIONS

Overall, there is insufficient evidence to determine the superiority of different protocols or adjunctive strategies to improve tooth maintenance during SPT. No trials evaluated SPT versus monitoring only. The evidence available for the comparisons evaluated is of low to very low quality, and hampered by dissimilarities in outcome reporting. More trials using uniform definitions and outcomes are required to address the objectives of this review.

Effect of local application of curcumin and ornidazole gel in chronic periodontitis patients

Objective:

The objective of this study is to evaluate the comparative effect of curcumin and ornidazole in treating chronic periodontitis.

Materials and Methods:

Twenty individuals of both sexes aged between 27 and 53 years diagnosed with chronic periodontitis and having pocket depths >5 mm bilaterally were selected for this study, in a split-mouth design. Examination of plaque index, probing pocket depth, and clinical attachment level was measured for each patient. The patients received a complete prophylaxis including scaling and root planing after which, both test gels were injected into the two experimental sites chosen, that had probing depth (PD) >5 mm and were located in symmetric quadrants. Pocket PD, clinical attachment loss, and plaque index were recorded at days 0 and 30.

Results:

At 1-month evaluation, curcumin group showed a significant decrease in pocket PD, plaque index, and clinical attachment loss when compared to the ornidazole group.

Conclusion:

The results show a more favorable outcome with curcumin than ornidazole gel, thus curcumin can be used as an adjunct to nonsurgical periodontal therapy.

Should Antibiotics Be Prescribed to Treat Chronic Periodontitis?

Although scaling and root planing is a cost-effective approach for initial treatment of chronic periodontitis, it fails to eliminate subgingival pathogens and halt progressive attachment loss in some patients. Adjunctive use of systemic antibiotics immediately after completion of scaling and root planing can enhance the degree of clinical attachment gain and probing depth reduction provided by nonsurgical periodontal treatment. This article discusses the rationale for prescribing adjunctive antibiotics, reviews the evidence for their effectiveness, and outlines practical issues that should be considered before prescribing antibiotics to treat chronic periodontitis.

Evaluation of ciprofloxacin and metronidazole encapsulated biomimetic nanomatrix gel on Enterococcus faecalis and Treponema denticola

BACKGROUND

A triple antibiotic mixture (ciprofloxacin; CF, metronidazole; MN, and minocycline; MC) has been used for dental root canal medicaments in pulp regeneration therapy. However, tooth discolorations, cervical root fractures, and inadequate pulp-dentin formation have been reported due to the triple antibiotic regimen. Therefore, an antibiotic encapsulated biomimetic nanomatrix gel was developed to minimize the clinical limitations and maximize a natural healing process in root canal infections. In this study, minimal bacterial concentrations (MBC) of the selected antibiotics (CF and MN) were tested in 14 representative endodontic bacterial species. Then MBC of each CF and MN were separately encapsulated within the injectable self-assembled biomimetic nanomatrix gel to evaluate antibacterial level on Enterococcus faecalis and Treponema denticola.

RESULTS

Antibiotic concentrations lower than 0.2 µg/mL of CF and MN demonstrated antibacterial activity on the 14 endodontic species. Furthermore, 6 different concentrations of CF and MN separately encapsulated with the injectable self-assembled biomimetic nanomatrix gel demonstrated antibacterial activity on Enterococcus faecalis and Treponema denticola at the lowest tested concentration of 0.0625 µg/mL.

CONCLUSIONS

These results suggest that each CF and MN encapsulated within the injectable self-assembled biomimetic nanomatrix gel demonstrated antibacterial effects, which could be effective for the root canal disinfection while eliminating MC. In the long term, the antibiotic encapsulated injectable self-assembled biomimetic nanomatrix gel can provide a multifunctional antibiotic delivery method with potential root regeneration. Further studies are currently underway to evaluate the effects of combined CF and MN encapsulated within the injectable self-assembled biomimetic nanomatrix gel on clinical samples.

Systemic anti-microbial agents used in periodontal therapy

Periodontitis is an infectious disease with marked inflammatory response, leading to destruction of underlying tissues. The aim of periodontal therapy is to eradicate the pathogens associated with the disease and attain periodontal health. This is achieved by non-surgical and surgical therapy; however, mechanical debridement and topical application of antiseptics may not be helpful in all cases. In such cases, adjunctive systemic antibiotic therapy remains the treatment of choice. It can reach micro-organisms at the base of the deep periodontal pockets and furcation areas via serum, and also affect organisms residing within gingival epithelium and connective tissue. Before advising any anti-microbial agent, it is necessary to have knowledge of that agent. The aim of this review article is to provide basic details of each systemic anti-microbial agent used in periodontal therapy. The points discussed are its mode of action, susceptible periodontal pathogens, dosage, its use in treatment of periodontal disease, and mechanism of bacterial resistance to each anti-microbial agent. It might be of some help while prescribing these drugs.

Antimicrobial therapy in periodontitis: the use of systemic antimicrobials against the subgingival biofilm

OBJECTIVES

The aim was to answer three relevant questions: can systemic antimicrobials be efficacious if the biofilm is not disrupted? Can the type of debridement of the subgingival biofilm impact upon the clinical outcomes of the adjunctive antimicrobial therapy? Is the efficacy of the adjunctive systemic antimicrobial therapy dependent on the quality of the debridement of the subgingival biofilm and the sequence debridement-antibiotic usage?

MATERIAL AND METHODS

Relevant papers were searched, critically analysed and their data were extracted.

RESULTS

For the first question, studies assessing susceptibility of bacteria in biofilms, and clinical studies evaluating systemic antimicrobials as monotherapy, were reviewed. For the second question, clinical studies comparing systemic antimicrobials as adjuncts to non-surgical debridement or to periodontal surgery and clinical trials using systemic antibiotics with periodontal surgery were evaluated. For the third question, a previous systematic review was updated.

CONCLUSION

If systemic antimicrobials are indicated in periodontal therapy, they should be adjunctive to mechanical debridement. There is not enough evidence to support their use with periodontal surgery. Indirect evidence suggests that antibiotic intake should start on the day of debridement completion, debridement should be completed within a short time (preferably <1 week) and with an adequate quality, to optimize the results.

Application of chitosan gel in the treatment of chronic periodontitis

Local administration of antibiotics in periodontal therapy can be provided with an appropriate delivery system. The purpose of this study was to evaluate the clinical effectiveness of chitosan, both as a carrier in gel form and as an active agent in the treatment of chronic periodontitis (CP). The chitosan gel (1% w/w) incorporated with or without 15% metronidazole was prepared and applied adjunctive to scaling and root planing (SRP) in comparison to SRP alone (control group-C), in CP patients. The clinical parameters such as probing depth (PD), clinical attachment level, the amount of gingival recession, plaque index, gingival index, and gingival bleeding time index were recorded at baseline and at weeks 6, 12, and 24. In all groups, significant improvements were observed in clinical parameters between baseline and week 24 (p < 0.05). The reductions in PD values were 1.21 mm for Ch, 1.48 mm for Ch + M, and 0.94 mm for C groups. No complications related to the chitosan were observed in patients throughout the study period. It is suggested that chitosan itself is effective as well as its combination with metronidazole in CP treatment due to its antimicrobial properties.

Local versus systemic adjunctive antibiotic therapy in 28 patients with generalized aggressive periodontitis

BACKGROUND

Although the use of systemic antibiotics has been studied in patients with generalized aggressive periodontitis (formerly rapidly progressive periodontitis), the use of adjunctive tetracycline fibers in these patients has not been reported. The purpose of the present study was to compare the clinical response of local versus systemic antibiotic treatment as adjuncts to scaling and root planing in patients with GAgP.

METHODS

After initial therapy and full-mouth scaling and root planing (SRP), 30 patients were randomly assigned to 1 of 2 antibiotic treatment groups. Probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were recorded with an automated probe prior to SRP at baseline (BL) and 15, 30, 41, and 54 weeks later. Three months after SRP, the patients were treated with amoxicillin/clavulanic acid (500 mg tid; SRP + AUG group) or with local tetracycline fiber in pockets with PD > or =5 mm (SRP + TCF group).

RESULTS

In both treatment groups, PD decreased significantly from BL to week 54 (6.2+/-1.5 mm to 4.7+/-1.4 mm for SRP + TCF and 6.5+/-1.4 mm to 4.2+/-0.6 mm for SRP + AUG). However, there was no statistically significant difference between the 2 groups in pocket reduction. Similarly, in both treatment groups, there were small but significant gains in CAL from BL to week 54 (12.0+/-1.8 mm to 11.3+/-1.8 mm for SRP + TCF and 12.3+/-1.5 mm to 11.2+/-1.2 mm for SRP + AUG). The difference in CAL gain between the 2 groups was not statistically significant. At the final examination, both groups showed significant PD reduction and CAL gain (P <0.001) compared to BL. The frequency and percentage of bleeding sites decreased significantly in both groups. At week 54, this decrease was significantly greater in the SRP + AUG group (31.67% for SRP + TCF versus 3.85% for SRP + AUG).

CONCLUSIONS

These results indicate that the local delivery of tetracycline by a fiber or the systemic administration of amoxicillin/clavulanic acid given 3 months after scaling and root planing produced similar clinical outcomes over the 9-month observation period.

A 2-step non-surgical procedure and systemic antibiotics in the treatment of rapidly progressive periodontitis

BACKGROUND

In the last few years knowledge about periodontal infections has increased enormously, nevertheless practitioners are still seeking guidelines for suitable treatment concepts.

METHODS

The aim of this study was to examine the effect of doxycycline, metronidazole, and clindamycin used adjunctively in a 2-step nonsurgical procedure in patients with rapidly progressive periodontitis (RPP). The first step included scaling, root planing, and polishing (SRP) in each quadrant using 4 to 5 visits. The second step included full-mouth enhanced root planing (RP) and wound dressing in 1 or 2 visits after SRP and the beginning of antibiotic therapy. Forty-eight patients (mean age 32.4 years) with generalized RPP, with an average of 16 sites with probing depths (PD) deeper than 8 mm, and high counts of Porphyromonas gingivalis were randomly assigned to 4 different groups: group 1 (doxycycline) n = 12, group 2 (metronidazole) n = 15, group 3 (clindamycin) n = 11, and group 4 (control group; no antibiotic treatment) n = 10. Clinical evaluations, including plaque index (PI), sulcus bleeding index (SBI), probing depth (PD), clinical attachment level (CAL), and bacteriological and crevicular cell sampling, were done at baseline (BL), 3 weeks after SRP, and 6 and 24 months after RP.

RESULTS

After the first step (SRP), we observed an improvement of PI and SBI in all 4 groups, but did not see any statistically significant PD reduction 3 weeks after SRP compared to baseline. However, 6 and 24 months after the second step (RP) we observed a significantly greater reduction of PD in groups 2 and 3 and a significantly greater CAL gain in comparison to groups 1 and 4. After 24 months, the attachment level gain in group 1 and group 4 was less than 1.5 mm, and less than 1.0 mm in PD site categories 6 to 9 mm and >9 mm. PI showed no significant difference between the groups throughout the period after SRP until 24 months, compared to 3 weeks after SRP. SBI decreased most in the metronidazole and clindamycin groups. P. gingivalis and Actinobacillus actinomycetemcomitans were almost completely eradicated in these 2 groups 24 months after RP. In addition, the phagocytotic capacity of crevicular polymorphonuclear neutrophils was increased in groups 2 and 3 after the second step.

CONCLUSIONS

The present results show that metronidazole and clindamycin are effective antibiotics when used adjunctively in a 2-step nonsurgical procedure of scaling and root planing in RPP patients.

Nonsurgical periodontal therapy in 2000: a literature review

BACKGROUND

This article addresses the advantages and limitations of nonsurgical periodontal therapies to treat patients with mild-to-moderate chronic periodontitis.

TYPES OF STUDIES REVIEWED

Controlled clinical trials were selected that assessed the efficacy of the following treatment methods: mechanical instrumentation, ultrasonic débridement, supragingival irrigation, subgingival irrigation, local drug delivery, administration of systemic antibiotics and host-response modulation. Evidently, data with regard to alterations of probing depth, clinical attachment levels and inflammatory status were evaluated.

RESULTS

Comparison of the data from test and control groups revealed the following results. Manual and ultrasonic débridement can be used to treat most patients with mild-to-moderate chronic periodontitis. Patients who do not practice optimal plaque control can enhance their personal hygiene procedures by using supragingival irrigation. Subgingival irrigation usually does not provide any benefit beyond that achieved with root planing. Systemic and locally delivered antimicrobial agents appear to be most beneficial among patients who do not respond to conventional treatment. Host modulation may enhance root planing modestly.

CLINICAL IMPLICATIONS

The data indicate that most patients with mild-to-moderate periodontitis can be treated with nonsurgical therapies. However, clinicians need to be aware of the limitations of each technique with regard to the magnitude of improvement that it can induce at specific sites.

Changes in the periodontal status of patients undergoing bone marrow transplantation

BACKGROUND

Patients receiving an HLA-matched bone marrow transplant (BMT) from a relative or unrelated donor undergo a permanent alteration of their immune system, followed by a prolonged period of immunodeficiency. This study aimed to examine alterations in the periodontal status of patients over 6 months post-bone marrow transplantation.

METHODS

Thirty-seven patients scheduled for bone marrow transplantation participated in this study. One calibrated examiner carried out periodontal examinations (clinical and radiographic) immediately prior to and at 3 and 6 months after transplantation. All patients followed an intense oral care program. Subgingival plaque samples were analyzed by enzyme-linked immunosorbent assay (ELISA) for the presence of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Prevotella intermedia. Data were subjected to statistical analyses to determine the relationships between the frequency distribution of the radiographic and clinical variables over time.

RESULTS

Gains in clinical attachment level (CAL) of > or =2 mm at 4 or more sites from baseline to 6 months post-BMT were noted in 9/16 patients (56%), while 6/16 (38%) patients experienced a loss of CAL > or =2 mm at 4 or more sites in the same period. At a site level, 4.8% of sites exhibited a gain in CAL > or =2 mm between baseline and 3 months post-BMT while 2.3% of sites showed a loss of CAL > or =2 mm in the same period. From baseline to 6 months, a gain in CAL of > or =2 mm was recorded at 3.1% of sites, and 2.4% of sites experienced a loss of > or =2 mm. A significant improvement in the gingival index occurred between all sequential time periods when assessed at a site level. At a patient level, 11/18 (61%) patients showed a significant change in gingival index between baseline and 3 months and 10/16 (63%) between baseline and 6 months. There was no significant relationship between clinical changes and the prevalence of the periodontal pathogens at the various time periods.

CONCLUSIONS

An improvement in periodontal health was recorded between baseline and 6 months post-transplantation. Most of the improvement in periodontal status was noted in the first 3 months after BMT, with a slight decline in periodontal health between 3 and 6 months post-transplant. No significant alteration was noted in the prevalence of periodontal pathogens during the study period.

Antibiotic resistance in oral/respiratory bacteria

In the last 20 years, changes in world technology have occurred which have allowed for the rapid transport of people, food, and goods. Unfortunately, antibiotic residues and antibiotic-resistant bacteria have been transported as well. Over the past 20 years, the rise in antibiotic-resistant gene carriage in virtually every species of bacteria, not just oral/respiratory bacteria, has been documented. In this review, the main mechanisms of resistance to the important antibiotics used for treatment of disease caused by oral/respiratory bacteria--including beta-lactams, tetracycline, and metronidazole--are discussed in detail. Mechanisms of resistance for macrolides, lincosamides, streptogramins, trimethoprim, sulfonamides, aminoglycosides, and chloramphenicol are also discussed, along with the possible role that mercury resistance may play in the bacterial ecology.

The use of locally delivered metronidazole in the treatment of periodontitis. Clinical results

Local delivery of antimicrobials has been investigated as a possible method for controlling and treating periodontal disease. A number of antimicrobial agents have been studied both as adjunctive therapies with scaling and root planing and as stand-alone chemotherapies. More recent investigations have focussed on the delivery of antimicrobials in sustained-release formulations designed to maintain effective concentrations of drug within the periodontal pocket. This article provides an overview of the development of the use of locally-delivered metronidazole in periodontal therapy and the current state-of-the-art of the technique. It is concluded that treatment with local delivery of metronidazole seems to be as effective as scaling and root planing in untreated as well as in recall subjects. However, there are reasons to suggest that local delivery of metronidazole should not be used as a substitute for conventional treatment of periodontal disease, since side-effects of long-term use and repeated use are not known. The antibiotic regimen should preferably be used as an adjunct to surgical and non-surgical therapy.

The role of local drug delivery in the management of periodontal diseases: a comprehensive review

This review article evaluates the role of local drug delivery systems in the management of periodontal diseases. The efficacy of several local delivery devices (i.e., tetracycline fibers, metronidazole and minocycline gels, chlorhexidine chips, and doxycycline polymer) which are either commercially available in the United States or abroad, or are currently under consideration for Food and Drug Administration (FDA) approval are discussed. The drug delivery systems are assessed with regard to their functional characteristics, effectiveness as a monotherapy, as compared to scaling and root planing, and ability to enhance conventional therapy. Furthermore, controversies associated with local delivery are addressed (e.g., induction of bacterial resistant strains, the efficacy of systemic versus local drug delivery, and whether local drug delivery should function as an alternative or as an adjunct to conventional treatment).

Antibiotic resistance mechanisms in bacteria of oral and upper respiratory origin

Over the past 20 years, antibiotic resistance has increased in virtually every species of bacteria examined. In this paper, the main mechanisms of antibiotic resistance currently known for antibiotics used for treatment of disease caused by oral and upper respiratory bacteria will be reviewed, with an emphasis on the most commonly used antibiotics. The possible role that mercury, which is released from silver amalgams, plays in the oral/respiratory bacterial ecology is also discussed, as it relates to possible selection of antibiotic resistant bacteria.

A clinical and microbiological evaluation of systemic and local metronidazole delivery in adult periodontitis patients

The present study describes results on selected clinical and microbiological parameters obtained by treatment with local (Elyzol) and systemic (Flagyl) use of metronidazole alone and/or mechanical subgingival debridement in adult periodontitis. Patients were randomly divided into local and systemic treatment groups each comprising 5 individuals in each of whom 4 sites (one site/ quadrant) with a probing depth of > or = 5 mm were selected and treated with separate treatment modalities. The overall treatment design provided 6 different test groups. Groups of quadrants received: (1) scaling and root planing; (2) local metronidazole treatment; (3) systemic metronidazole treatment; (4) local metronidazole combined with scaling and root planing; (5) systemic metronidazole combined with scaling and root planing; (6) no treatment. The microbiological and clinical effects of treatment modalities were monitored over a period of 42 days. All treatments resulted in clinical improvements (gingivitis, probing pocket depth, attachment level) except for the untreated group. Parallel to the clinical changes, all treatments reduced the number of total bacteria and proportions of obligately anaerobic microorganisms. Although both of the combined treatment groups responded to therapy with better resolution of infection that the pure mechanical and pure metronidazole treatments, local metronidazole in combination with scaling and root planing seems to be more effective in terms of producing both clinical and microbial improvements.

Sustained local delivery of chlorhexidine in the treatment of periodontitis: a multi-center study

The safety and efficacy of a degradable, subgingivally placed drug delivery system containing 2.5 mg chlorhexidine (CHX) were evaluated in a randomized, blinded, multi-center study of 118 patients with moderate periodontitis. A split-mouth design was used to compare the treatment outcomes of scaling and root planing (SRP) alone with the combined use of SRP and the CHX in pockets with probing depths of 5 to 8 mm. The two maxillary quadrants were used for the two treatment arms of the study. Scaling and root planing was performed at baseline only, while the CHX was inserted both at baseline and at 3 months. Clinical and safety measurements including probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) as well as gingivitis, plaque, and staining indices were recorded at baseline, and at 1, 3, and 6 months. The average PD reduction in the CHX-treated sites was significantly greater than in the sites receiving SRP alone at both 3 and 6 months with a mean difference of 0.42 mm (P < or = 0.01) at 6 months. The reduction in CAL at the treated sites was greater than at the SRP sites, although the difference was statistically significant at the 6-month visit only. An analysis of patients with initial probing depths of 7 to 8 mm (n = 56) revealed a significantly greater reduction in PD and CAL in those pockets treated with CHX compared to SRP at both 3 and 6 months. The mean differences between test and control sites at 6 months were 0.71 mm and 0.56 mm PD and CAL respectively.

Treatment of periodontal disease based on microbiological diagnosis. Relation between microbiological and clinical parameters during 5 years

The purpose of this study was to assess the clinical effect of treatment aimed to suppress Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis below detection level and Prevotella intermedia below 5% of the cultivable periodontal pocket flora. Sixteen patients and a total of 111 periodontal pockets with probing depth > or = 6 mm were included in the study. Twelve patients and a total of 77 sites completed the 5-year study. The results demonstrated clinical improvement of probing depth and gain of clinical attachment level of 3.4 mm and 1.2 mm, respectively. Treatment to eliminate indicator bacteria continued for 3 years before the aim was fulfilled. In order to eliminate A. actinomycetemcomitans from a majority of the sites, a combination of surgery and generalized tetracycline treatment was performed. A recolonization or regrowth of the indicator bacteria exceeding detection levels took place in several sites. The presence of A. actinomycetemcomitans. P. gingivalis, and P. intermedia, alone or in combination, correlated with attachment level change on the individual level. No such correlation was obtained by using presence of plaque, bleeding on probing, or three other bacteria (Campylobacter rectus, Eikenella corrodens, and Fusobacterium nucleatum) not used as treatment goal markers.

Microbial flora in the acute phase of periodontitis and the effect of local administration of minocycline

Periodontitis, similar to other infectious diseases, is known to progress as chronic inflammation with recurrent acute phases. The purpose of this study was to clarify the microbiological composition of the acute phase and to compare the bacterial flora with that of comparable chronic periodontal pockets. We also evaluated the effect of application of minocycline gel locally on the change in the microflora in the acute pockets. Microbial flora from the subgingival pockets of 28 patients in the acute phase of periodontitis and of 12 patients in a comparable chronic phase as the control were investigated by various bacterial culture methods including TS blood agar and TSBV plates. Minocycline gel was applied to the acute periodontal pockets. Changes in the microbiological proportion and clinical parameters at one week after baseline examination were followed by dark-field analysis, culture method, and indirect immunofluorescence technique. Characteristic features of bacterial proportions in the acute site were observed as an increase in Bacteroides forsythus. The number of Porphyromonas gingivalis and black pigmented anaerobic rods also increased. Application of minocycline gel in the acute pocket without any debridement produced improvement in clinical symptoms at one week. Black-pigmented anaerobic rods, P. gingivalis, and B. forsythus decreased significantly at one week after the application. Results indicate that periodontopathic bacteria including B. forsythus and P. gingivalis were predominant in the acute phase of periodontitis and a locally delivered antibiotic may be effective as an alternative modality of treating the acute inflammation.

Distribution of biotypes and antimicrobial susceptibility of Actinobacillus actinomycetemcomitans

Eighty isolates of Actinobacillus actinomycetemcomitans from 30 Brazilian periodontitis patients were examined to determine the distribution of biotypes and in vitro antimicrobial susceptibility. Seventy-seven percent of the isolates belonged to biotype X. All A. actinomycetemcomitans isolates were susceptible to cefoxitin, imipenem and tetracycline.

Clinical and microbiological effects of controlled-release locally delivered minocycline in periodontitis

The clinical efficacy of minocycline in a subgingival local delivery system was evaluated alone (M) or as an adjunct to scaling and root planing (M + SRP), in comparison to scaling and root planing (SRP) or to no subgingival treatment (NoTx) in adult periodontitis. Fifty-one adult patients with > or = 7 mm periodontal pockets demonstrating the presence by culture of Porphyromonas gingivalis (Pg), Prevotella intermedia (P(i)), or Actinobacillus actinomycetemcomitans (Aa) were randomized into one of the above 4 treatment groups. All sites > or = 5 mm in the most diseased quadrant in each patient received the therapy. Other quadrants were not treated. All patients received standardized oral hygiene instructions at the beginning of the study. At 0, 1, 3 and 6 months following therapy the 7 mm experimental sites were evaluated for selected periodontal pathogens by DNA probe analysis. At these same time points, the plaque index, gingival index, and bleeding on probing were evaluated as well as probing depth and relative clinical attachment level which were assessed by means of an automated probe. Probing depth reduction with M + SRP was significantly greater than all other groups at one month and significantly greater than NoTx and SRP at 3 months. There were no differences in probing depth reduction among groups at 6 months. At 6 months the gain in clinical attachment level was significantly greater for SRP than for either the NoTx or M groups. The prevalence of Pg decreased significantly in the M and M + SRP groups at one month.(ABSTRACT TRUNCATED AT 250 WORDS)

Clustering of fibronectin adhesins toward Treponema denticola tips upon contact with immobilized fibronectin

Treponema denticola has been shown to bind to immobilized fibronectin (Fn) by its tips. Yet labeling of cells in suspension with an Fn-gold conjugate to localize the Fn adhesins shows that they are distributed in patches along the entire cell length. Subsequent experiments have shown that the number and proportion of tip-oriented cells increase with time, suggesting that Fn contact stimulates T. denticola to rearrange adhesins toward its tips. To test this hypothesis, T. denticola cells were allowed to migrate in a 2% methylcellulose column toward nitrocellulose filters coated with Fn, laminin, bovine serum albumin, or phosphate-buffered saline. Cells close to and distant from the filters were collected, labeled with Fn-gold probes, and examined by transmission electron microscopy. The number of gold particles on each of 20 cells was counted, dividing each cell into thirds along its length: the end third with the most label (end 1), the middle third, and the end with the least label (end 2). The mean number (+/- standard deviation) of gold probes per third was calculated. Fn-gold probes clustered toward one end of T. denticola cells when in contact with Fn-coated nitrocellulose, with > 55% of probes in end 1. In contrast, no clustering toward T. denticola ends occurred with laminin-, bovine serum albumin, or phosphate-buffered saline-coated filters or in the absence of a filter. Blocking access of the T. denticola cells to the Fn-coated nitrocellulose filter by placing an uncoated filter between them prevented clustering of Fn-gold. Removal of T. denticola cells from direct contact with the Fn-coated filter did not promote redistribution of clustered probes. These data suggest that T. denticola is stimulated to cluster Fn adhesins irreversibly toward its tips when it migrates into contact with immobilized Fn. This might be significant for establishing multiple adhesive interactions with host cells and ligands.